The hallways are significantly less crowded when the players remaining in the 2011 Main Event go on break. The amount of chatter at the tables is drastically reduced. The only thing that seems to have increased is the number of fans watching the action from the rail.

It’s an annual transition at poker’s world championship that usually comes around Day 3, which fell on Thursday this year, when the money bubble nears and players start to realize the magnitude of the event.

“You can definitely tell the difference,” said Patrick Poirier, the current chip leader. “It’s a lot more serious. Some people were kind of scared to play hands on the first two days, but now most of us are 100 big blinds deep or short so everyone is opening up.”

At the end of play Thursday, 852 players were left out of a starting field of 6,865. Only 159 of them will prove unlucky enough to lose their $10,000 buy-in, as the Main Event pays 693 places this year.

In all likelihood, the tournament will reach the money within the first few hours of play Friday and those who cashed will rejoice. The nearing of the money bubble on Day 4 is notorious for freezing players who are left without many chips, as they try to fold their way into cash.

Most professionals and those with more intimidating chip stacks advise playing more aggressively on Day 4 to take advantage of the perceived dead money up for grabs.

“I think you gradually work your way up and Day 3 or 4 is when you start making your moves to get some chips,” said Poker Hall of Famer Mike Sexton earlier this WSOP.

Sexton, a one-time WSOP bracelet winner, isn’t still in the field as he busted during his Day 2 session. That’s nothing to be ashamed of, however, as the majority of notable players have made their exit by now.

Consider the numbers of people left in the following categories.

One remains from last year’s Main Event final table. That’s Joseph Cheong, who finished in third last year after losing in the biggest pot in WSOP history. Cheong has around 480,000 chips headed to Day 4.

Two former champions are still in the field — Phil Hellmuth, who won the 1989 Main Event, and Robert Varkonyi, the 2001 champion. Varkonyi and Hellmuth are below average with approximately 168,000 chips and 71,000 chips, respectively.

Three players who made the ‘November Nine’ final table since the WSOP instituted the four-month layoff in 2008 are alive. In addition to Cheong, 2008 November Nine members Dennis Phillips and Darus Suharto are still playing.

When the day began, Poirier was one of the most anonymous faces at the Rio. According to the Hendon Mob poker database, Poirier has only $36,180 career tournament earnings.

But ESPN cameras surrounded the 25-year old semi-professional from Tupper Lake, N.Y., after he became the first player to hit the 1 million-chip threshold.

“This is my last shot this summer and then maybe I’ll go back to school,” Poirier explained. “I’ve played a ton of tournaments here and at the Venetian and had terrible results, with only three cashes.”

Poirier won a handful of sizable pots to seize the chip lead. To cross over a million, his Ace-King took down an opponent’s pocket Jacks.

None of Poirier’s hands were the most talked about of Day 3, though. That dubious honor belonged to Las Vegas pro Shaun Deeb, who was on the wrong end of a bad beat in what was the largest pot of the Main Event at the time.

Poker professional Shaun Deeb rubs his face during the World Series of Poker main event at the Rio Monday, July 11, 2011.

Max Heinzelmann, a 21-year old from Germany, put in a sixth bet before the flop to put Deeb all-in. Deeb immediately called with pocket Aces, while Heinzelmann could only show Ace-6 off-suit for an attempted bluff gone awry.

But Heinzelmann hit an improbable 6 on both the flop and river to take nearly all of Deeb’s chips. Deeb met his elimination shortly afterward and went to twitter to air out his frustration.

“I am just in shock,” Deeb posted.

Bad beats and untimely knockouts will continue for the next five days until nine come out of the pack to make the Main Event final table.

Poirier is expecting cautious play from most players on the edge of the money bubble Friday, but hasn’t decided if he’ll try to use it to his advantage.

“I’m not sure,” Poirier said. “It depends on my table. I’ve played real aggressive so far, and opened about 70 percent of the pots, but usually I’m tighter. We’ll have to see.”